The union representing most Metro police officers hopes to resolve differences with Metro management, despite its filing of a lawsuit against the transit agency, a union attorney said.

The complaint filed by the union in U.S. District Court in D.C. describes a deteriorating relationship between Metro and union officials. The suit asks the court to bar Metro from certain actions and seeks unspecified monetary damages and attorneys' fees.

"It is not our goal to make things difficult for Metro," lawyer Justin Keating said. "We want to fix problems, not make them."

Keating declined to provide additional details. He said in an e-mail that he did not want to disrupt "what could be an early sign of progress" in recent days.

Metro spokeswoman Cathy Asato said the transit authority does not comment on pending litigation.

According to Keating, about 350 of Metro's 420 sworn police officers are in the union, which is part of the Fraternal Order of Police.

The lawsuit says Metro management had questioned several of the officers who attended the union meeting where the no-confidence vote was held, and ordered them to provide written statements if they were on duty at the time. The lawsuit says that for the past 20 years, on-duty officers have attended the monthly union meetings while remaining responsive to radio calls.

According to the suit, Taborn phoned Duncan on Jan. 20 and demanded to know what happened at the meeting.

At the meeting, the union passed a resolution saying that Taborn had disregarded the collective-bargaining agreement that expired Sept. 30, neglected officer safety issues and failed to fix a faulty police radio system.

Metro has been engaged in arbitration with the union over the collective-bargaining agreement. The lawsuit says Metro representatives have said that Duncan should be voted out of office because he was not acting in the best interests of the union, and also complained when Duncan, a detective, wore his gun to one of the arbitration sessions.